Instead of calculating the area of 3 #6 bars manually, use Table 3 (Area of Reinforcement).
If you are preparing for the PE (Principles and Practice of Engineering) exam or learning the code: pca notes on aci 31819
The code's equations for development length (ld) are straightforward but involve multiple modification factors (casting position, coating, lightweight concrete, etc.). The PCA Notes offer a single, unified worksheet to plug in variables and get ld directly. Additionally, a full table of standard hook development lengths for Grade 60 rebar is provided. Instead of calculating the area of 3 #6
Example excerpt:
Given ( f'_c = 4,000 , \textpsi ), ( f_y = 60,000 , \textpsi ), ( b = 12 , \textin ), ( d = 22.5 , \textin ), ( M_u = 300 , \textkip-ft ).
Compute ( R_n = M_u / (\phi b d^2) ), find ( \rho ), then ( A_s = \rho b d ). Additionally, a full table of standard hook development
Perhaps the most significant change is the codification of the Direct Design Method and Equivalent Frame Method into a new Chapter 12, separate from the traditional empirical method. The PCA Notes dedicate over 30 pages of examples to comparing the old and new slab design methods.
ACI 318-19 increased the minimum reinforcement required for beams and one-way slabs to control cracking. The PCA Notes provide corrected tables comparing the old 200/fy formula with the new, more rational 0.5√(f'c)/fy requirement, showing exactly when the new rule governs.